Package bpfmon

https://github.com/bbonev/bpfmon/

While tcpdump shows what packets are going through the
network, bpfmon will show how much in terms
of bytes per second and packets per second in a
nice pseudo-graphical terminal interface.

bpfmon also supports monitoring an iptables rule that
is selected by command line option or selected from a
menu.

For even bigger flexibility bpfmon supports getting the
counters from a custom script.

Version: 2.60